Add MODAL WINDOW Subscribe to blog??

Is there a way to Add MODAL WINDOW “Subscribe to blog” like the widget?? They clould subscribe directly in modal window? I cannot customize header or use h1 and h2 right? if not is there a way to have the subscribe to blog on a fullwidth page without the sidebar and placing in main area of page? I am trying to work the blog, writing articles etc. Want to try and build a following.